Well safety valve system

ABSTRACT

A well safety valve system for controlling the fluid flow through a well tubing in which a retrievable safety valve is positioned in the well tubing by providing a shut-off valve in the tubing above the safety valve which allows the safety valve to be controlled by fluid pressure from the well surface but which closes off the tubing pressure from the surface control fluid for isolating tubing pressure from the control fluid prior to retrieving the safety valve. A safety valve landing nipple connected in the well tubing for receiving the retrievable safety valve. A fluid control line connected between the landing nipple for supplying control fluid through the safety valve, and the shut-off valve connected in the well tubing above the landing nipple. The shut-off valve having first and second ports, the first port connected to the fluid control line leading to the landing nipple, and a second port connected to the control fluid pressure at the well surface. The valve including a valve element for opening and closing communication between the first and second ports.

United States Patent [191- Tausch [111 3,7d6fi63 [451 Jan.22,1974

1 WELL SAFETY VALVE SYSTEM [75] Inventor: Gilbert H. Tausch, Houston, Tex.

[73] Assignee: Cameo, Incorporated, Houston, Tex.

[22] Filed: Mar. 30, 1973 211 Appl. No.: 346,706

Primary Examiner-James A. Leppinlg Attorney, Agent, or F irm-Jefferson D. Giller; James F. Weiler; William A. Stout [57] ABSTRACT A well safety valve system for controlling the fluid flow through a well tubing in which a retrievable safety valve is positioned in the well tubing by providing a shutoff valve in the tubing above the safety valve which allows the safety valve to be controlled by fluid pressure from the well surface but which closes off the tubing pressure from the surface control fluid for isolating tubing pressure from the control fluid prior to retrieving the safety valve. A safety valve landing nipple connected in the well tubing for receiving the retrievable safety valve. A fluid control line connected between the landing nipple for supplying control fluid through the safety valve, and the shut-off valve connected in the well tubing above the landing nipple. The shut-off valve having first and second ports, the first port connected to the fluid control line leading to the landing nipple, and a second port con- I nected to the control fluid pressure at the well surface.-

The valve including a valve element for opening and 3 Claims, 7 Drawing Figures 1 WELL SAFETY VALVE SYSTEM BACKGROUND OF THE INVENTION It is conventional to provide a retrievable subsurface well safety valve such as the type B manufactured by Camco, Incorporated for protecting producing wells in which the safety valve is controlled by an external pressure from the well surface. However, in a retrievable safety valve, the flow control pressure from ahydraulic tubing leading to the well surface, such as shown in US. Pat. No. 3,078,923, is generally connected di- 'rectly to a landing nipple receiving the safety valve. Of course, if the safety valve is removed, the internal bore of the well tubing is in communication with the flow control pressure which is undesirable. Means for isolating the tubing pressure from annulus control fluid pressure is shown in US. Pat. Nos. 3,292,706 and 3,627,042.

The present invention is directed to an improved well safety system utilizing a conventional safety valve landing nipple connected in a well tubing for receiving a retrievable type safety valve. A shut-off valve is provided above the landing nipple in the well tubing for isolating the bore of the well tubing from the control fluid pressure supplied from the well surface which controls the FIG. 2A is an enlarged elevational view, partly in cross section, of the well tubing of the well safety valve system of the present invention showing the top portion of the housing of the shut-off valve,

FIG. 2B is a continuation of FIG. 2A showing a shut off valve of the present invention in the open position,

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, particularly to FIG. 1,

' a typical well installation, generally referred to by the operation of the safety valve, prior to retrieving the subsurface safety valve.

SUMMARY The present invention is directed to a well safety valve system for controlling the fluid flow through a well tubing in which a retrievable safety valve is adapted to be positioned in a landing nipple connected in the well tubing and controlled by fluid pressure through a conduit from the well surface. A flow control line is connected between the landing nipple and a valve connected in the well tubing above the landing nipple. The valve includes first and second ports, the first port being connected to the fluid control line and the second port is connected through a conduit to the control fluid pressure at the well surface. The valve includes a valve element for opening communication between the first and second ports for allowing the safety valve to be controlled by the fluid pressure from the well surface. But the valve element may be actuated to close communication between the first and second ports thereby isolating the interior of the well tubing from the surface control fluid prior to removing the safety valve.

Yet a further object of the present invention is the provision of a sliding sleeve type valve connected between the fluid control conduit from the well surface and the landing nipple which receives the retrievable well safety valve for isolating the interior of the well tubing from the control fluid.

Other and further objects, features and advantages will be apparent from the following description of a presently preferred embodiment of the invention, given for the purpose of disclosure and taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view, partly schematic, and partly in cross section, illustrating one type of typical retrievable safety valve installation in a well bore utilizing the present invention,

reference numeral 10, is shown including a well head 12 for receiving well production through a well tubing 14 inside of a casing 16 separated from the tubing 14 by a packer 18 for receiving well fluids from a formation 20. A retrievable safety valve 22 is provided, for example only, type B of Camco, Incorporated, shown positioned in a landing nipple 24 in the well tubing 14 and held in place by a conventional well lock 26.

The safety valve 22 is conventionally controlled by fluid pressure from the well surface through a fluid conduit 30 leading from the well surface downwardly. Referring to FIG. 2C, the safety valve 22 is releasably connected into the landing nipple 24 by a conventional well lock 26 such as an-M lock of Camco, Incorporated in which locking dogs 32 engage a locking recess 34 in the landing nipple 24. When the safety valve 22 is secured in the landing nipple 24, seals 36 and 40 seal against the landing nipple 24 on opposite sides of a landing nipple port 40. The port 40 is supplied with a control fluid, such as hydraulic fluid, for admission to the safety valve 22 through openings 42 to control the actuation of the valve 22. However, it is to be noted that when the valve 22 is removed from the landing nipple 24 the supply port 40 will be open providing communication between the interior of the well tubing 14 with the control fluid.-If the port 40 is connected to a line conduit 30 leading to the well surface and well head 12, the presence of tubing pressure in the control system may be undesirable.

The present invention is directed to providing a valve connected to the well tubing 14 above the landing nipple 24 to isolate the interior of the tubing 14 from the control fluid for the safety valve 22.

Referring now to FIGS. 2A and 2B, a valve generally indicated by the reference numeral includes a housing 52 adapted to be suitably connected in the well tubing 14 such as by threads 54 at the top end and threads 56 (FIG. 2C) to the landing nipple 24. The valve 50 includes a first port 58 and a second port 60. The first port 58 is connected to the port 40 in the landing nipple 24 by a fluid control line 62. The second port 60 is connected to the control fluid at the well surface by a hydraulic control conduit 30 to the well surface. The valve 50 includes a valve element sliding sleeve 64 for opening and closing communication between the first port 58 and the second port 60. The valve 64 includes a first seal 66, a second seal 68 and a third seal 70. The sliding sleeve valve element 64 includes an internal passageway 72. When the recess 72 is aligned with the seal 68, fluid may bypass between the ports 58 and 60. In this position, as best seen in FIG. 28, control fluid may pass from hydraulic line 30 through the ports 60 and 58, through the flow control line 62, and to the port 40 in the landing nipple 24 for controlling the safety valve 22. The valve element 64 is normally held in the open or operating position by a detent 74 on the valve housing 52 engaging a holding recess 76 on the valve element 64.

As best seen in FIG. 5, the valve element 64 has been shifted downwardly moving the passageway 72 below the seal 68 whereby the outer periphery 80 of the valve element 64 bridges across the seals 66, 68 and 70 blocking fluid flow between the ports 58 and 60. Therefore, even if the valve 22 is retrieved from the landing nipple 24, the interior of the tubing 14 is isolated from communication with the control fluid at the port 60. When the valve element 64 is shifted downwardly, as shown in FIG. 5, the detent 74 is disengaged from the holding recess 76 and engaged in a holding recess 78 for releasably retaining the valve element 64 in the closed position.

Referring now to FIGS. 28 and 5, suitable means may be provided 'on the valve element 64 for shifting the sleeve 64 upwardly and downwardly for opening and closing the communication between the ports 58 and 60. Thus, a first engaging recess 82 having a downwardly directed shoulder 84 may be provided for coacting with a suitable and conventional shifting tool, such as Camco Z lock, for moving the sleeve 64 upwardly for opening the'valve 50. In addition, a second engaging recess 86 is provided on the interior of the sleeve 64 having an upwardly directed shoulder 88 for engagement with a shifting tool for moving the valve element downwardly.

In operation, the safety valve 50 may be assembled in the well tubing 14 in the open position as show in FIG. 2. The valve 50 has a full opening bore 90 allowing the passage of the safety valve 22 or other well tools therethrough. The valve 50 is normally open allowing control of the safety valve 22 by fluid pressure from the well surface. If it is necessary to remove the safety valve 22, a shifting tool is lowered through the bore of the well tubing 14 to engage the engaging recess 86 and shoulder 88 for shifting the sleeve valve element 64 downwardly, as best seen in FIG. 5, closing communication between the ports 58 and 60. The safety valve 22 may then be removed, inspected or repaired and returned to its subsurface position in the landing nipple 24. A shifting tool can then be run down the tubing 14 and engage the engaging recess 82 and shoulder 84 of the sleeve valve element 64 and move the sleeve 64 to its upper position as best seen in FIG. 2B, placing the valve in the open position to allow surface control of the subsurface safety valve 22 to resume.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein. While a presently preferred embodiment of the invention has been given for the purpose of disclosure, numerous changes in the details of construction and arrangement of parts may be provided without departing from the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. In a well safety valve system for controlling the fluid flow through a well tubing including a safety valve landing nipple connected in the well tubing and adapted to receive a retrievable fluid controlled safety valve, the improvement comprising,

a fluid control conduit extending from the well surface downwardly for providing control fluid for controlling the safety valve,

a fluid control line connected to the landing nipple for receiving fluid pressure for controlling the safety valve,

a sliding sleeve valve connected in the well tubing above the landing nipple, said valve having first and second ports, the first port connected to the fluid control line, the second port-being in communication with the fluid control conduit, said sleeve movable between positions for opening and closing communication between the first and second ports.

2. The apparatus of claim 1 wherein said valve is a sliding sleeve type valve operable internally of the well tubing.

3. The apparatus of claim 1 wherein said valve includes an open bore of substantially the same size as the bore of the well tubing for allowing passage of well tools. 

1. In a well safety valve system for controlling the fluid flow through a well tubing including a safety valve landing nipple connected in the well tubing and adapted to receive a retrievable fluid controlled safety valve, the improvement comprising, a fluid control conduit extending from the well surface downwardly for providing control fluid for controlling the safetY valve, a fluid control line connected to the landing nipple for receiving fluid pressure for controlling the safety valve, a sliding sleeve valve connected in the well tubing above the landing nipple, said valve having first and second ports, the first port connected to the fluid control line, the second port being in communication with the fluid control conduit, said sleeve movable between positions for opening and closing communication between the first and second ports.
 2. The apparatus of claim 1 wherein said valve is a sliding sleeve type valve operable internally of the well tubing.
 3. The apparatus of claim 1 wherein said valve includes an open bore of substantially the same size as the bore of the well tubing for allowing passage of well tools. 